Folding carton with self-locking cover



Jan. 15, 1957 B. D. OSTEEN 2,777,629

FOLDING CARTON WITH SELFLOCKING COVER Filed Sept. 30, 1955 INVENTOR. B/mon' 1 D O 5 7"98 Fig.3 W Z United States Patent FOLDING CARTON WITH SELF-LOCKING COVER Belmont D. Osteen, Birmingham, Ala. assignor to Birmingham Paper Company, a corporation of Alabama Application September 30, 1955, Serial No. 537,753

2 Claims. (Cl. 223-36) This invention relates to cardboard containers such as are employed in the packaging of frozen food products, and for other uses, and has for an object the provision of a container of the character designated which shall include improved means for securing the cover in closed position.

Another object of my invention is to provide a collapsible cardboard container which shall include a cover portion which, upon closing, snaps into locked position with respect to the lower or box portion thereof and holds the cover securely in place.

A more particular object of my invention is the provision of a collapsible cardboard container including a box portion and a cover in which the cover shall have a longitudinally slitted inturned flap thereon engageable, when the container is closed, by an outturned flap on the side of the box portion to hold the cover in closed position.

A container embodying features of my invention is illustrated in the accompanying drawing, forming a part of this application, in which:

Fig. l is a perspective view thereof in open position;

Fig. 2 is a front elevational view with parts broken away and in section;

Fig. 3 is an enlarged sectional view taken along the line IHHI of Fig. 2; and,

Fig. 4 is a partial sectional view taken along the line IV-IV of Fig. 3.

Referring to the drawing for a better understanding of my invention, I show a collapsible cardboard carton including a lower box portion having end walls and 11, side walls 12 and 13, and a bottom 14. The carton is formed from an integral blank with flaps 16 and 17 on the end walls 10 and 11 which are glued to the side wall 12, and tabs 18 and 19 on the side walls 13 which are glued to the end walls 10 and 11 to form the box portion. A cover portion 21 is hinged along the scored line 22 to the rear side Wall 12 and comprises end walls 23 and 24 and a front side wall 26. The side wall 26 is provided with tabs 27 and 28 which are glued to the end walls 23 and 24 of the cover 21. The end walls 10 and 11 are scored along diagonal lines 29 and 31 and the end walls 23 and 24 are scored along diagonal lines 32 and 33 whereby the carton may be collapsed to lie flat, all as is well understood in the art to which my invention relates. As will be apparent from the drawing and the description which is to follow my invention may be applicable to containers constructed in a way other than just described.

The particular features of the container which I claim as my invention is the provision of an improved locking means for the cover portion 21 when the container is closed, and which will now be described. Hinged along the upper edge of the front side wall 13 by a score line 36 is a downwardly inclined, ontturned flap 37 which extends the entire length of the front wall 13. The front wall 26 of the cover portion 21 is cut inwardly along downwardly divergent lines 37 and 38 to provide an upwardly inclined intumed flap 39. As shown in Fig. 1, the flap 2,777,629 Patented Jan. 15, 1957 2 39 is shorter than the flap 37 and the inclined cuts 37 and 38 provide upwardly divergent end portions 41 and 42. The flap 39 is slit along a line 43 which extends longitudinally the major portion of the length thereof.

When the box portion is filled with merchandise and' the cover portion 21 is closed down over the box portion as shown in Fig. 3, the end walls 23 and 24 of the cover portion telescope over the end walls 10 and 11 of the box portion and the side wall 26 of the cover portion telescopes over the side wall 13 of the box portion. With the cover portion 21 closed down, the upper edge of the flap 39 snaps into engagement with the upper side, or edge of the slit 43 and firmly locks the cover portion in place. It will be seen that as the cover portion 21 is closed down over the box portion, the flap 37 on the box portion, engaging with the outwardly flared ends 41 and 42 of the flap 39, cause the upper portion 39a of the flap, above the slit 43, to bow outwardly as shown in Figs. 3 and 4 of the drawing so that the upper edge of the slit 43, adjacent its ends, is engaged by the downwardly inclined ontturned flap 37 on the box portion to lock the box in closed position. It will be understood that in Fig. 3 of the drawing the box is shown empty and that when it is packed with merchandise, the wall 13 will be pushed outwardly so that the parts are in closer engagement than shown in the drawing. It will also be seen that the flap 37 cannot enter into the slit 43 and thus there can be no play between the box portion and the cover portion when .the cover is locked in place as just described.

From the foregoing, it will be apparent that I have devised a collapsible cardboard container which is simple of design and construction and one which embodies an improved locking means for the cover.

While I have shown my invention in but one form, it will be obvious to those skilled in the art that it is not so limited but is susceptible of various changes and modifications without departing from the spirit thereof, and I desire, therefore, that only such limitations shall be placed thereupon as are specifically set forth in the appended claims.

What I claim is:

1. In a cardboard container including a lower rectangular box portion and an upper cover portion hinged along the upper edge of one side of the box portion, a downwardly inclined outturned flap along the upper edge of the opposite side of the box portion, a side wall on the cover portion disposed to fit over the last mentioned side of the box portion, an upwardly inclined inturned flap on the side wall of the cover portion formed by downwardly divergent cuts in the cover portion the inner ends of which are joined by a scored line to form a hinge for the flap, said flap having a longitudinal slit therein the lower side of which is disposed to be engaged by the lower edge of the flap on the box portion when the cover is closed.

2. A container as defined in-claim 1 in which the flap on the side wall of the cover portion is formed by downwardly divergent cuts in the said side wall inwardly of the ends thereof and in which the said side wall is scored along a line joining the inner ends of said cuts to form a hinge for said flap, and in which the flap on the side wall of the box portion is longer than the flap on the 

